Electrical connector



Sept. 19, 1961 3,001,171

F. A. SCHULTZ ELECTRICAL CONNECTOR Filed Dec. 27, 1955 5 Sheets-Sheet 1d2 d1 c2 58 A J WHN Q .-.:-TOUT 106 I Q3 OUT 54 30 i V 56 I .i 52 58 in:102 R 1"" 4 T INVENTOR '4 H6 I04 I24 4ii:.| 2 2 BY FREDERICK A. SCHULTZATTORNEY Sept. 19, 1961 F. A. SCHULTZ ELECTRICAL CONNECTOR 5 SheetsSheet2 FIG. 5 B

Filed Dec. 27, 1955 IN V EN TOR I H BY FREDER CK A SC ULTZ ATTORNEYSept. 19, 1961 F. A. SCHULTZ ELECTRICAL CONNECTOR 5 Sheets-Sheet 3 FiledDec. 2'7, 1955 FIG. 3

BY FREDERICK A. SCHULTZ FIG. 4

ATTORNEY 3,001,171 ELECTRICAL CONNECTOR Frederick A. Schultz,Poughkeepsie, N.Y., assiguor to International Business MachinesCorporation, New York, N.Y., a corporation of New York Filed Dec. 27,1955, Ser. No. 555,456 1 Claim. (Cl. 339217) This invention relates toelectrical connectors and more particularly to electrical connectorsused for connecting a multiplicity of lead wires to a correspondingmultiplicity of electrical contact elements on an edge of a circuitcard.

Due to the complexity of present day electronic computers, a very largenumber of electronic components must be utilized and space savingconsiderations become important in order to limit the excessive size ofthe equipment. These computers are generally comprised of circuitsutilizing fairly standard basic circuits such as flipflops, emitterfollowers, inverters, AND circuits, and OR circuits which now may makeuse of components such as small germanium diodes, transistors, resistorsand condensers. It is desirable to have the circuits organized so thatthey may be accessible for servicing in the machine, and also may beremoved as units for servicing at a place remote from the piece ofelectronic equipment itself. To make the circuit removable as a unit,the circuit components are usually permanently connected to circuitcards, each of which is made detachable as a unit.

These basic circuits lend themselves to compact arrangement on thecircuit cards, whereon conductive tabs on one edge are used for externalconnection thereto. By inserting the tabs of the circuit cards in novelsockets which have plug sleeves, plug wires may be utilized to make theinterconnections between the cards and it then becomes possible to useautomation processes. The automation process permits the programming ofa machine which inserts the plug wires, to make possible mass productionof computers and yet provide for slight changes or additions to standardcomputer circuitry as required.

It is, therefore, an object of this invention to provide selectiveflexible connections between circuits on a circuit card or cards.

A further object of the invention is to provide a conductive connectorfor electrically connecting a circuit card equipped with conductive tabsto a plurality of pin terminals of electrical plug wires.

A still further object of the invention is to provide an electricalconductive connector between the circuit card and the plug wire made ofan inexpensive unitary strip of metal.

A still further object of the invention is to provide a non-conductivesocket having a plurality of first channels, each of which isdimensioned to receive the terminal tabs on the edge of said cards.

Another object of the invention is to provide a nonconductive sockethaving a plurality of second channels intersecting each first channeland adapted for supporting, isolating, and protecting the conductiveconnectors.

Other objects of the invention will be pointed out in the followingdescription and claim illustrated in the accompanying drawings, whichdisclose, by way of example, the principle of the invention and the bestmode which has been contemplated of applying that principle.

In the drawings:

FIG. 1 is a side view of a nonconductive socket-indicating the frontface of a circuit card mounted therein, and having portions of thesocket broken away to show internal parts thereof.

FIG. 2 is a partial detail front view of the non-con- .ductive socketindicating in section, the circuit cards mounted therein.

FIG. 3 is a rear face View of the circuit card of FIG. 1.

FIG. 4 is a sectional View taken on the line 44 in FIG. 2.

FIG. 5A is an enlarged front elevational detail of the conductiveconnector.

FIG. 5B is a top detail view of the conductive connector taken on theline 5B5B of FIG. 5A.

FIG. 5C is a developed view of the conductive connector drawn on asmaller scale.

FIG. 6 is a circuit diagram of a typical diode AND circuit.

FIG. 7 is a circuit diagram of a typical transistor emitter follower.

FIG. 8 is a view in perspective illustrating the structure of a computerunit with one of its gates partially opened.

Before describing the details of the invention, a general descriptionwill be given. Generally, the circuit cards of the invention have aspecific standard arrangement of plated holes, printed terminal tabs andprinted wiring which results in a most compact arrangement of electroniccomponents thereon for all different types of computer basic circuits.The plated holes are arranged in rows across the circuit card and theleads of the electronic components are inserted therein preparatory toconnection thereto by dip soldering. The clip soldering of the entirecircuit card is made possible by the placing of the electroniccomponents on the front face only, of the circuit card, which fact, inturn, is made possible by the plated hole arrangement and the fact thatthe wiring is printed parallel to the rows of plated holes on the frontface of the card, and perpendicular thereto on the rear face.

A non-conductive socket for the circuit cards contains a plurality offirst channels each first channel being dimensioned to receive an edgeof a circuit card, and each of the first channels being intersected by aplurality of second channels. The second channels contain conductiveconnectors, each of which engages a terminal tab at the edge of thecard. The conductive connector is a unitary strip of metallic stockhaving a shoulder carrying a spring contact oppositely disposed to aplurality of sleeves. The sleeves extend through holes in the rear ofthe socket and are engageable with plug wires for electricalinter-connections between circuit cards. The cards are closely arrangedfront face to rear face in the first channels of the socket and so testterminal tabs are provided on the outside edge of the circuit card topermit testing of the circuits while in the machine. The sockets aresupported side by side at their ends by a pair of mounting rails.

Referring now to FIG. 8, a standard main frame for a computer or otherlarge scale electronic apparatus may be observed. The main frameconsists of two gates 19 and 12, one of which, gate 12 is swingable onhinges 13 forwardly away from gate 10. Each gate contains a number ofrows of circuit cards 14, only the edges of which can be seen in FIG. 8.The inside of gate 10 shows the plug wiring 16 which are used to makethe electrical connections between the circuit cards 14 in gate 1%, andthere is similar plug wiring 16 at the rear of gate 12 which is notshown. Before describing the structure for mounting the circuit cards,the nature of the card itself and the usual circuitry thereon will bedescribed.

FIGS. 6 and 7 illustrate two typical circuits that are utilized incomputer circuitry. FIG. 6 shows an AND circuit consisting of componentssuch as germanium diodes 18 and a resistor 20', connected to a terminaltab 21 which is externally connected to a supply voltage of +10 voltsD.C. An AND circuit requires that there be two input signals placed onterminal tabs In, in order to get an output signal on the terminal tabOut. FIG. 7 indicates an emitter follower which is ordinarily used toincrease thepower of a signal without distortion or in- 3 version, andcomprises a PNP transistor 22, a condenser 24 and resistors 26, 28 and30. Other basic circuits may be utilized which contain inductances.

Referring to FIG. 1, there is illustrated the. front face of a circuitcard 14 comprising a component mounting wafer 32 made of any suitableinsulating material such as phenolic. The wafer 32 has holes 11 punchedthere through in a standard pattern, to be presently described. Theholes are conductively plated around the inside circumference and alsoso as to have a rim of conductive material on both faces of the Wafer,by any well known printed circuit fabrication technique, such as metalspraying, photoetching, etc. Smaller holes 36 at the edges are alsoconductively plated around the inside circumference but instead of arim, the conductive material on the face are rectangularly shaped andextended to the edge of the circuit card 14, to form terminal tabs 2. Atthe same time, any wiring between plated holes h, between tabs 1, andbetween holes h and tabs 1 are plated on the wafer. This printed wiringmay be placed on either face of the card 14, the rear face of the cardbeing shown in FIG. 5.

7 It has been determined that a standard arrangement of the printedwiring permits a more flexible and compact arrangement, as will be morefully described presently.

Referring to FIG. 3, a number of rows of plated holes are shown labeledrows a1, a2, [21, b2, b3, 01, c2, and dll, d2. Each hole in a row isspaced only far enough apart from the next one in that row so that aprinted wire may be placed between them without contacting the rim ofthe plated holes 34. Rows a1 and a2 are spaced far enough apart fromeach other to permit the circuit components such as resistors,condensers, inductances and diodes, to be placed between them in amanner so that the leads of the circuit components may be inserted inhorizontally aligned plated holes (FIG. 1). This standard holearrangement also lends itself to automatic insertion of the componentsinto the plated holes. Generally, the resistors, condensers andinductances are placed between rows all, and a2, rows c1 and 02, or rowsd1 and d2. In circuits utilizing diodes, the diodes are generally placedbetween rows b1 and 152, but it is apparent they may be placed in theother rows. A row b3 is placed on the card, having plated holes itplaced close to row b2, each of the holes of which is placed just belowand between holes in each pair of plated holes in row 122. The pair ofholes of row b2 and the respective adjacent plated hole of row 123 areutilized as connections to a socket 40 (FIG. 1) of a transistor T. Whentransistors are mounted in the plated holes of rows b2 and b3, the holesof row [21 are not used. It is to be noted that the components are allmounted on the front face of the wafer 32, thus permitting the back faceto be lowered into solder, in the well known dip soldering process,which by capillary action draws the solder up into the plated holes toprovide soldered connections to the circuit component leads mountedtherein.

To illustrate the use of the standard hole pattern and explain thestandard wiring arrangement, the circuit card of FIGS. 1 and 3, whichcarries seven of the emitter follower circuits of FIG. 7, will bedescribed in more detail. FIG. 7 shows the schematic connections of anemitter follower, all the wires shown in FIG. 7 running at the frontface of the circuit card, unless noted rear. The collector C of atransistor 22 is connected to a plated hole 42, and via a wire 44 on thefront face of the circnit card to a 6.5 volt terminal tab 46. Theemitter E is connected to a plated hole 43 which is connected to a wire56 printed on the rear face and electrically connecte to a terminal tabOut and to a test terminal tab T-Out. The terminal tab Out is connectedvia front face wire 52, a plated hole 54, the resistor 30, the platedhole 56, front face wire to a +10 volt terminal tab 60. The base 13 isconnected via a plated hole 62 and via a rear face wire 64, plated hole66, rear face wire 68,

a plated hole 76, resistor 23, a plated hole 72, front face 4 wire 74,plated hole 76, rear face wire 78 to a 15 volt terminal 80. Plated hole62 is connected by a front face wire 82, a plated hole 84 and resistor26 to a plated hole 86. Condenser 24, which has its leads connected toplated holes 33 and 99 is parallel with resistor 26 because of the frontface wire connection -82 between plated holes '84 and 88, and a frontface wire connection 92 between plated holes 86 and 9t). Plated hole 86is connected via rear face wire 94 to terminal tab In and test terminaltab T- In.

From FIG. 1 it can be observed that there are seven similar emitterfollowers on the one card. The terminal tabs 1 in the middle aregenerally for input and output signals, while the terminal tabs t oneither side of the signal voltages are for service voltages. Thispermits the service voltages to be brought up vertically on either sideof the card, to the plated hole row it will be connected to, and then onthe front face a printed wire may be run parallel to the plated holerows, as do for instance leads 7'4, 44 and 58. With wires parallel tothe hole rows, all other long wires to be run perpendicular to the rowswill be run on the rear face. In FIG. 3, it can be observed that all theprinted wires run substantially perpendicular to the plated hole rows.

The circuit cards 14 are mounted in non-metallic sockets 96 (FIGS. 1, 2and 4), each of which has cut into a top surface 98 thereof firstchannels 100. Each of the first channels is made wide enough toaccommodate an edge of a circuit card 14, and there are eight firstchannels Hit} in each socket 96. The non-metallic socket 96 is longenough to accommodate two circuit cards 14 side by side (see FIG. 1) andwide enough to accommodate four circuit cards 14 front face to rear face(see FIGS. 2 and 4). Each first channel 109 has a plurality of secondchannels 102 intersecting it and perpendicular thereto. The bottom ofthe second channel 102 is set a little deeper into the socket 96 thanthe bottom of the first channel 100. There are three cylindricalopenings 164 through the socket 96 from the bottom of the secondchannels into the bottom surface 105 of the socket 96. The secondchannels 102 and the openings 1% are arranged in this manner toaccommodate a conductive connector 106. The sides of second channels actto electrically isolate the conductive con- V nectors 106 from eachother and to physically protect them.

Conductive connector 166 shown in FIG. 5C as it 18 stamped out, is aunitary metallic strip having a shoulder 1G3 supporting three legs 112oppositely disposed to two tongues lift. Connector 106 has its legs'112rolled to form cylindrical sleeves 114 and its tongues 110 are then bentinto the position clearly indicated in FIG. 5A to form a spring clip 16.in EEG. 5C, the two outside legs 112 are shown to have slots 1111 cutinto the outside edges close to the lower portion of the legs 112. Whenthe cylindrical sleeves 114 are formed, the little tabs 113 below theslots 111 are tapered as shown in FIG. 5A and act as looking tabs.

Each of the connectors 106 is inserted into a second channel 192 untilthe bottom edge of the shoulder 108 rests at the bottom of the secondchannel 102. The sleeves 114 project through the bottom surface 105 ofthe socket 96 but they are protected by ridges across the bottom surface105 of the socket 96. When the sleeves 114 are inserted into theopenings 104, the tapered locking tabs 16S make the insertion processvery easy. As the tab moves into the opening 104, the lock- 'mg tab 105is compressed and when the locking tab 105.

comes through the bottom of the opening, the'locking tab snaps back andits upper edge locks against the lower surface of the socket 96. In thisposition, when the circuit cards 14 are inserted into the first channels100, the spring clips 116 make contact with the terminal tabs t on theW0 faces of the circuit card. FIG. 4 shows the plugs 122 of a plug wire16 connected between two sleeves 114 to thereby make connections betweenthe circuits of different circuit cards 14.

From FIGS. 2 and 8, it can be observed that each socket 96 is mounted onrails 124 by screws 126 through a hole on each end thereof. Thus, inFIG. 8, the gates and 12 have a plurality of rails 124 which carry thesockets 96, which in turn, support the circuit cards 14. Interconnectionbetween the circuit cards are made by plug Wires 16, and any testing ofthe circuits of the circuit cards can be done by putting test clip leadson the test terminal tabs t at the edge opposite to the edge in thesocket '96.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaim.

What is claimed is:

A connector for electrically connecting, within a nonmetallic socket, apair of electrically connected conductive edge strips on each side of acircuit card to three ex ternal electrical wire terminals: comprising anon-metallic socket having a plurality of equi-diameter holestherethrough; a unitary strip of conductive flexible metallic stockhaving a shoulder; three sleeves extending in parallel relation fromsaid shoulder; each sleeve engageable with one of said electrical wireterminals; said center sleeve being connected to the center of saidshoulder and notched on each side in a position near said shoulder; eachof the outer two sleeves having a notch close to its end; the portion ofeach outer sleeve below said notch being bent in the form of a lockingtab; the outside diameter of the locking tab just below the notch beinggreater than the diameter of the socket hole and tapering downwardly toa diameter less than the socket hole; said locking tab adapted to bedepressed as said connector is inserted forwardly, sleeve end first,into the holes of said socket; said locking tab adapted to restore to aposition, when the connector is in the fully inserted condition, so thatthe top of the locking tab at the notch bears against the non-metallicsocket to lock the connector against backward movement in thenon-metallic socket; and a pair of tongues; each tongue extending fromthe side of the outside sleeve facing the center sleeve; said tonguescurled inwardly towards each other to form a conductive spring contactengageable with said pair of conductive edge strips.

References Cited in the tile of this patent UNITED STATES PATENTS2,540,037 Vough et a1. Jan. 30, 1951 2,575,161 Deakin Nov. 13, 19512,707,272 Blitz Apr. 26, 1955 2,707,274 Kough Apr. 26, 1955 2,711,523Willis June 21, 1955 2,754,453 Noell July 10, 1956 2,937,357 Kennedy May17, 1960

